Recent widespread incorporation of digital audio file archiving, compression, encoding, transmission, decoding, and playback has led to the possibility of new opportunities at virtually every stage of the digital audio process. It was recently shown that the preferred ratio of voice-to-remaining audio (VRA) differs significantly for different people and differs for different types of media programs (sports programs versus music, etc.). See, “A Study of Listener Preferences Using Pre-Recorded Voice-to-Remaining Audio,” Blum et al., HEC Technical Report No. 1, January 2000.
Specifically, VRA refers to the personalized adjustment of an audio program's voice-to-remaining audio ratio by separately adjusting the vocal (speech) volume independently of the separate adjustment of the remaining audio volume. The independently user-adjusted voice audio information is then combined with the independently user-adjusted remaining audio information and sent to a playback device where a further total volume adjustment may be applied. This technique was motivated by the discovery that each individual's hearing capabilities are as distinctly different as their vision capabilities, thereby leading to individual preferences with which they wish (or even need) to hear the vocal versus background content of an audio program. The conclusion is that the need for VRA capability in audio programs is as fundamental as the need for a broad range of prescription lenses in order to provide optimal vision characteristics to each and every person.